Mixers



Sept. 22, 1959 POUR: 2,905,450

MIXERS Filed June 21, 1957 s Sheets-Sheet 2 E. E. POURE Sept. 22, 1959 MIXERS 3 Sheets-Sheet 5 Filed June 21, 1957 United States Patent MIXERS Emile Edouard Pour, Montreuil-sous-Bois, France Application June 21, 1957, Serial No. 667,127 Claims priority, application France June 26, 1956 6 Claims. (Cl. 259-84) The present invention relates to the known type of mixer, the tank of which is supported between two vertical circular end-plates resting on rollers and is able to rotate about the common axis of the said end-plates, the

mixing members inside the tank being formed by helical members parallel to the common axis and driven in rotation through the medium of gearing from a motor drive applied to a shaft which is arranged along the common axis. The mixers of this type constructed up to the present time comprise two mixing helixes which rotate in two cylindrical enclosing cavities, symmetrical with respect to the mean longitudinal plane of the tank containing the common shaft.

In accordance with the invention, the tank contains in one position of symmetry with respect to the helixes at the bottom of the tank around the common shaft, at

least one helix for the top of the tank, rotating in a cylindrical enclosing cavity formed in the cover of the tank, the group of helixes at the bottom of he tank and the helix or group of helixes at the top of the tank being operated, through the medium of reduction gears mounted on the circular end-plates at the two extremities of the tank, respectively by separate driving shafts mounted along the extension of the common shaft at the two extremities of the mixer. These shafts are driven, either by two separate motors mounted on the circular endplates, or by a fixed driving installation driving each of the shafts through a pulley and belt.

The mixer comprises an upper tank helix in the vertical plane of symmetry of the bottom tank helixes passing through the common axis, or alternatively it comprises two upper tank helixes in positions symmetrical with the bottom tank helixes, with respect to the common shaft.

The tank is held between the circular end-plates by three cross-stays arranged in the vertical plane of symmetry, one along the common shaft, at each extremity, and the shafts of the helixes pass through the wall of the tank with dismantlable packing glands in the space between the end Wall of the tank and the adjacent endplate.

The invention will be described by way of example with reference to the accompanying drawings which show one form of construction of a mixer in accordance with the invention, comprising four helixes, and in which:

Fig. 1 is a longitudinal vertical section of the machine, the left-hand half of the section being taken in a vertical plane which passes through the common axis, and the right-hand half being taken in a vertical plane parallel to the axis of the helixes of one side of the tank passing through the line I-I of Fig. 7;

Fig. 2 is a transverse cross-section of the tank provided with its cover, the helixes not being shown;

Fig. 3 is a detail view to a large scale of a packing gland for the shaft of a helix;

Fig. 4 is a cross-section along the line IVIV of Fig. 3, looking towards the left of that figure;

Fig. 5 is a cross-section taken along the same line IVIV of Fig. 3, looking towards the right of that figure;

2,905,450 Patented Sept. 22, 1959 Fig. 6 and Fig. 7 show in elevation from the exterior the circular end-plates, the first being the left-hand endplate and the second the right-hand end-plate of the: machine in Fig. 1.

In the embodiment shown, the tank in accordance with the invention and indicated as a unit by 1, is in transverse cross-section circumscribed by a square (see Fig. 2) and comprises a hollow body formed of two molded members 2 and 3 and a cover 4. The tank assembly 13 shaped internally to provide a plurality of intercommunicating substantially cylindrical recesses which in the plane of cross-section (Fig. 2) are defined by four circles symmetrically located with respect to two mutually perpendicular planes. In the two recesses 5 of the bottom of the tank, two helices 6 rotate, two further helices 8 being housed in the two recesses 7 of the top of the tank, these two groups of two helices being operated independently as will be seen below.

The tank is carried between two circular end-plates 9 and 10, resting on rollers 11, so that the tank can carry out a complete rotation about the intersection line of the two planes of symmetry, which is also the common axis of the end-plates 9 and 10. The tank is fixed to these end-plates at each side by three cross-stays, one of which 12 is on the common axis, the two others 13 being symmetrically located above and below said axis respectively in the mean vertical plane.

7 The helices are extended by end-shafts 14 which pass through the end walls 15 of the tank through packing glands indicated as a whole at 16, these glands being carried by the adjacent end-plates through the medium of bearings. In its passage through an end wall 15 of the tank, a shaft 14 is provided with a protecting sleeve 17 (see Figs. 3 to 5). The body 18 of the packing gland, in two parts, is centered in a hole drilled in the said wall and carries a flange 19 fixed by screws 20 against this wall. The cap of the packing gland is formed of two half-rings 21 which are coupled together by a ring 22 gripping two half-bosses 23, the half-rings 21 providing a support for the clamping nuts 24 which are screwed on threaded studs 25 fixed on the body 18.

By reason of this construction, it is easy to dismantle the packing glands in the fairly narrow space between the ends of the tank and the adjacent circular end-plate. When the nuts 24 are removed, the ring 22 can in fact be pulled off and each half-ring 21 is then removed so as to change the packing of the gland, after which the latter is re-assembled. After removing the cap and the packing, the body 18 of the packing gland can also be removed.

The groups 6 and 8 of two helices are operated from the opposite ends of the mixer. In the example shown, the helices 6 of the bottom of the tank are operated from the left-hand extremity of Fig. 1 and the helices 8 of the top of the tank from the right-hand extremity. The shafts 14 of the helices at the non-driving extremity are carried by the adjacent end-plate by ordinary bearings 26. The shafts 14 of the driven extremity are carried in the end-plate by thrust bearings 27 and extend be yond the end-plate by a coupling shaft end with a conical bearing surface 28 on which is keyed a gear 29 or 30. For one of the helices (see Figs. 6 and 7), this gear 29 is of large diameter and is directly engaged with a pinion 31 keyed on an end-shaft 32 or 33 mounted on the common axis in the line of extension of the central crossstay 12. For the other helix, this gear 30 is of smaller diameter and is coupled to the said pinion 31 by an intermediate Wheel 34. The two helices of the same set thus rotate in opposite directions at different speeds.

The arrangement of the driving members is the same at both extremities of the mixer. The driving shaft 32 or 33 is carried by bearings 35 between the end-plate 3 901210 and a'hood 36fixed on the end-plate and coveringthegears. It projects .from theoutsideot. this latter and carries a driving pulley 37 or 38 so that it can be driven by a belt from a separate fixed motor (not shown). Theiintermediate gearss34 ofeachextremit'y are mounted Ont-bearings l1i'Sl1flfiS'39 :fixedto the endplat'ei9 or 10.

The drives ot-ithetworextremities of the mixer being independent can be carried out at difierent speeds, either byvthegmotors rotating. at diflierenhspeeds oribythe transmissions-of their movement to the shafts 32 being eflected through difierent reduction gearing. In addition, the couplings through gears of the two extremities may be in difierent ratios. The fixed drivingsource maybe commonvandthe transmissions may be providedlwith clutches. For-:the drive .oteach end shaft, two motors could also'be used andmounted on the end-plates, but itiisrmore convenient. for the motors tobe fixed.

Themixer describedv enables mixing operations to be carriedout intwo stages-certain mixtures requiring first ofi alla-slow rate of stirring and then a rapid stirring and thiswwithout thereibeing any need to modify the 'reduction ratios of the drive of the .two pairs of helices. In:tl1efirst operating stage, the tank is placed in such manner-that one .of the pairs of helices is at the lower portionnand the mixing operation. is carried out with these. helices. Then'the-motor drive of these helices being stopped and the .tank having been rotated through 180? about the common axis, the. other motor drive is startedup so as to complete the mixing operation at awdifierent mixing speed. The advantage is that the mixing in two stages is carried outinthe same machine, the appropriate motor drives being put into operation in-suceessiom They could also operate together since this.does'not prevent-the rocking movement of the tank. If; so desired, it is also possible to rotate the tank in a continuous manner during the mixing operation so as to ensure the alternate action of the helices which rotate at difieren't speeds. The loading of the tank is normally eflectedin theposition at which the cover is at its uppermost position and it is the helices of the bottom of the tank whichcarry out the mixing in the first stage, so that it is not necessary to rotate the tankin order to commence theoperation. Thetank can be emptied, after removal of the cover in its top position, by turning the tank around as in the case of known mixers of the type referred to.-

The invention is of course in no way limited to the embodiment described by way of example. ticular; asthe mixing member at the top of the tank, there could be a single. helix located in the vertical plane of symmetry, the top of the tank and the cover then having a different shape from the bottom 'ofthe tank so as to. de-lirnit around this helix the enclosing cylindrical cavity necessary.

What I claim is:

1. A mixer of the type describedand comprising, in combination, azbase. member, rollers supported on said- In par-- base, a pair of spaced vertical circular end plates rotatably supported onsaid-rollers-for rotation about a common axis, a tank supported between said end plates, said tank comprising a lower portion, an upper portion and a cover, detachably secured together, the assembly being shaped internally so as to define a plurality of substantially cylindrical recesses parallel to said axis, at least one rotatable lower mixer helix mounted in the lower portion of said tank, at least one rotatable upper mixer helix mounted in the upper portion of said tank, said upper and lower helices being disposed symmetrically with respect to a verticalplane passing through said common axis, each said helix being partially enclosed in one of said recesses, separate driving means for individually driving-'saidlupper and lower mixer helices, separate driving shafts for the upper and lower helices respectively, said shafts being mounted one in each of said end plates on the common axis, and reduction gears 1 provided between said driving shafts and the driven in opposite directions and at difierent relative speeds helices, said gears being mounted on said end plates, whereby said upper and lower helices rotate independently at different relative speeds in opposite directions.

2. A mixer as claimed in claim 1, in which saidseparate driving means each comprise'a motor actuating the corresponding driving shaft, said motor being mounted on thecorresponding circular end plate.

3. A mixer asclaimed in claim 1, and further comprising a pulley mounted on each said driving shaft and a belt-"coupling said pulleys each'to a fixed driving installation.

4. A mixer as claimed in claim 1, and comprising two upper helices and two lower helices, said driving means comprising means for rotating said upper helices and means for rotating said lower helices in opposite directions and at different relative speeds.

5. A- mixer asclaimed in claim 1, and comprising two upper helicesin symmetrical relation with two bottom helices with respect to said common axis;

6. A mixer as claimed in claim 1, and further com-' prising three cross-stays supporting said tank between the circular end plates, said' cross-stays being disposed in the vertical plane of symmetry, one in's aid common axis, one abovesaidaxisand one below said axis.

References Cited in the file of this patent UNITED STATES PATENTS Re. 10,608" Dingle et al June 9, 1885 2,126,869 Burchenal et al. Aug. 16, 1938 2,215,976 Robinson Sept. 24, 1940 2,535,647 Millman et al. 1. Dec. 26, 1950 2,547,092 Poure Apr. 3, 1951 2,570,864 1 Rowlson a Oct. 9, 1951 2,572,063 Skipper Oct.'23, 1951 2,726,068 Howden Dec. 6, 1955 "2,794,626 Sterritt June 4, 1957 

